1. Field of the Invention
The present invention relates to a developing device for a reproducing machine or the like and, more particularly, to a developing device which is equipped with a supply hopper for supplying a developer to the inside of a developer bath.
2. Description of the Prior Art
In a developing device for a reproducing machine or the like, generally speaking, it is necessary to supply a developer corresponding to the amount consumed for development.
In the reproducing machine of the prior art, therefore, a supply hopper is disposed above the developing device to supply a developer corresponding to the replenishment amount therefrom to the developing device. If, however, the developer is held still in that supply hopper, it is stabilized to cause bridging phenomena thereby to make the supply of the developer difficult. The bridging phenomena means such phenomena that only the developer near the feed roller is supplied because the developer in the developer supply hopper is packed. Thus a space is formed between the feed roller and the developer located at the upper portion of the developer supply hopper thereby causing the supply of the developer impossible.
In the prior art, therefore, the supply hopper is periodically beaten or vibrated by a beater provided on the side of the supply hopper or a vibrator is additionally provided to the same hopper to apply a mechanical force to the stabilized developer thereby to prevent occurrence of the bridging phenomena.
However, this developing device of the prior art requires the beater and vibrator to raise its production cost and to complicate its construction. Moreover, the device of the prior art produces noises to deteriorate the office circumstances which should be quiet.